What is fold mountains

Fold moutains are actually formed by crust which have been uplifted and folded by compressional forces. This occurs along convergent plate boundaries where 2 plates move towards each other, between continental plates or between an oceanic and a continental plate. The crust and the rocks get bent and crumpled, and massive layers of Earth's crust gets uplifted as a result, forming spectacular fold mountains.

More well-know examples of fold mountains are the Himalayas in Asia and the Andes in South America.

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Origins of Fold Mountains

Fold mountains are created by uplift and folding of tectonic plates as they move towards each other and collide. This is known as a compressional plate margin. An example is the Andes Mountain range in South America(Nazca Plate colliding with the South American Plate)

The plates may be either 'continental and continental' or 'continental and oceanic'. The plates move towards each other, but there isn't a free space for them to move into because they are already touching each other. With two massive plates of rock pushing against each other and continually moving, all that rock has to go somewhere!

At a destructive plate margin where oceanic and continental plates collide, the oceanic plate is subducted, pulled under the continental plate - whilst the continental plate is crumpled upwards to form a mountain range. The Andes are an example of fold mountains formed at a destructive plate margin.

When two continental plates move towards each other, both plates are forced upwards in a series of folds. This caused big problems for early geologists who struggled to explain why they were finding fossils of sea creatures high up in mountains such as the Himalayas! We now know that the fossils got there due to uplift of sedimentary rocks found along the edges of the plates. (Previous suggestions often centered on religious myths / beliefs such as Noah's Great Flood.)

You can simulate this process using two flat strips of modeling clay or old carpet. Put them side by side and push them together. One or both will crumple up and form a mini mountain range on your table top.